1. Field of the Invention
This invention relates to methods for the production of composite pesticidal compositions and to the compositions produced thereby. More particularly, it relates to methods for producing granular composite compositions including at least two pesticidally active ingredients in combination such as an insecticidally active ingredient and a herbicidally active ingredient and to the composite combination products produced.
2. Description of Related Art
A wide variety of pesticidal compositions for use in treating plants have been known heretofore which include insecticidally active ingredients and/or herbicidally active ingredients. Additionally, a variety of methods for producing such pesticidal compositions are known and, particularly, methods for producing products including separate, individual ones of the pesticidal agents. For example, The Scotts Company LLC has previously offered a commercially available product under the trademark “Bonus” S for use as a broad leaf weed killer, particularly, in St. Augustinegrass, centipede, zoysia and carpetgrass lawns. This product consists of a herbicidally active Atrazine powder tacked onto a granular urea-formaldehyde fertilizer core material employing polybutene L-14 as the tacking agent.
Another currently available commercial product being offered by The Scotts Company LLC under the tradename “Turf Builder with Fire Ant Killer” is used primarily for fire ant control and consists of an insecticidally active solution of a pyrethroid ingredient (Bifenthrin) which is sprayed onto a granular urea-formaldehyde fertilizer.
However, there has been a continuing unfulfilled need to provide efficient and cost effective methods for producing granular composite compositions comprising combinations of certain pesticidally active ingredients such as mixtures of insecticidally active ingredients and herbicidally active ingredients as well as the unique compositions produced by such methods.
For example, it has been recognized heretofore that it would be of significant economic and functional benefit to provide improved methods for producing composite granular compositions that would solve several troubling problems which consumers have encountered in regard to lawn care in hot, dry climates such as found in the southern United States. In particular, it would be highly advantageous to provide methods for producing a unitary composite composition that is capable of killing and/or preventing fire ants in such lawns and would be effective for eradicating weeds from the lawns while providing enhancements in feeding and strengthening the lawns whereby preventing browning and bare spots in the grass under prevailing heat and drought conditions.
Also, it would be advantageous to provide such unitary, granular composite compositions which exhibit these desirable functional characteristics.
As noted above, a wide variety of pyrethroid compositions have been known to be effective active ingredients for inclusion in insecticidal formulations for controlling fire ants. However, problems have been encountered in attempting to formulate composite products containing pyrethroid compositions in combination with other pesticidally active ingredients. That is, the pyrethroid compositions have been known to exhibit solubility problems which render them commercially unacceptable for formulation as sprays to enable efficient and cost effective application on granular active ingredient substrates such as powdered herbicidally active ingredients or on granular inert carriers.
Specifically, it has been known that pyrethroid compounds such as alphamethrin, cyfluthrin cypermethrin (alpha, beta, theta, zeta), deltamethrin, fenpropathrin, fenvalerate, flucythrinate, fluvalinate and tralomethrin which are all cyano-containing compounds are only soluble in highly polar solvents.
However, it has been recognized that the use of such highly polar solvents to dissolve these pyrethroids results in solutions which lack the necessary tackiness to effectively adhere granular active ingredients to substrates when sprayed thereon. Furthermore, to the extent that solutions of these cyano containing pyrethroid insecticidally active ingredients are dissolved in the necessary highly polar solvents to produce sprays and are capable of being applied on granular active ingredient substrates such as herbicidally active ingredients, it has been found that the presence of the highly polar solvents in addition to reducing tackiness of the spray, also causes deterioration of the effectiveness of the composite active ingredients in the compositions including the insecticidally active pyrethroid and any other insecticidally or herbicidally active composition in the composite product.
However, no previously known methods have been available which are suitable for producing unitary, granular composite pesticidal compositions having the desired characteristics either because of process or product shortcomings such as the cost effectiveness of the methods, the ability to include the desired active ingredients efficiently and effectively in the composite compositions and the physical properties of the resulting compositions produced thereby.